This is a renewal proposal for a program of fundamental demographic research on the population of the Soviet Union. In the project;s first five years, fourteen papers have been published or accepted for publication. Substantial attention was given to evaluation and correction of Soviet demographic data. The investigators repeatedly found that conclusions based on uncritical acceptance of Soviet data were incorrect or misleading. After a decade-long hiatus, the Soviet government has begun to publish a substantial amount of demographic data. The new data fill in gaps for the past and also address areas for which there has previously been very little data published. The new date increase the possibilities for analysis of Soviet demographic patterns, and they supply reported figures for items that would have had to be estimated indirectly otherwise. However, it is already apparent that they are not without their problems. Thus, evaluation and correction of these new data are necessary, since their uncritical acceptance would likely also lead to incorrect or misleading conclusions. A primary aim of this project from its inception has been to estimate and analyze demographic patterns in the Soviet Union by region and especially by ethnic group, and to compare these patterns with those found in other populations. This task has been challenging because many demographic measures are not published consistently for regions of the Soviet Union, and very few data are published by ethnic group. Sufficient groundwork has now been laid by the investigators to produce ethnic-specific demographic estimates. In the next project period, much more progress on ethnic-specific estimates will be made because of the work to date and because of the new Soviet data. In addition, new data on cause of death and on morbidity will allow further testing of hypotheses about causes of levels and trends in mortality in the Soviet Union. In the new period, the analysis will be expanded to explicit comparisons with the population of China, with a special focus on those areas of northern China that contain ethnic groups that are also found in the Soviet Union. Two Chinese demographers will participate in this part of the analysis. Availability of microdata will allow the testing of hypotheses about the relative importance of ethnic group membership as compared to socioeconomic characteristics and geographic location in the determination of fertility and mortality and in the quality of demographic data that are produced.